At both sites, none of our new radiocarbon ages overlap at the calibrated 2σ range with the old series of rat bone dates from the same layers (Table S1) that were processed in 19, and all are younger than 1280 A. Locations of laughing owl bone sites, seed deposits, and seed test pits in New Zealand.Symbols show location of redated laughing owl bone sites (20, 21) (blue), seed deposits (red) mentioned in text, and test pits (black) examined during the search for seed sites, but which did not contain preserved seeds.Blue circles, our reexcavations; red circles, museum collections (see Table S1 for stratigraphic and other details).ages from previous studies (20, 21) also shown in their laboratory processing order (1995–19–1998) (40): open diamonds, archaeological sites (36); black diamonds, laughing owl sites (21), showing unusual bimodal distribution (36).A new dating approach is required to help determine the actual chronological sequence and pattern of ecological and anthropological change on Polynesian islands.We illustrate this approach here using New Zealand, the southernmost archipelago of East Polynesia, because it provides an excellent case study where an unresolved polarized debate persists about the time of initial human colonization (18) roost sites (20, 21) and distinctive rat-gnawed woody seed cases bearing the tell-tale incisor marks of seed predation found preserved in sediments (15, 22).This then suggests that the current indigenous people of New Zealand (Maori and Moriori) were neither of East Polynesian origin nor the first discoverers.However, this is inconsistent with analyses of New Zealand Pacific rat and Maori mt DNA (26, 31).
The Pacific rat currently exerts high predation pressure on seeds (43) and has been implicated in the extinction of several prehistoric plants (13, 44).D.), but all bones dated after 1996 are younger (36, 37) (Fig. Moreover, some rat bones from archaeological assemblages that were processed in 19 are significantly older than consistent dates on diverse materials from the same stratigraphic contexts (34, 35).Critics argued that this unusual bimodal distribution of ages according to when the bones were processed was due to inadequate pretreatment of small bones (33, 35 from Earthquakes #1, Predator Cave, and seven other South Island laughing owl sites from which the original 1995–1996 rat bone dates were derived (20, 21).2) showed that none was older than 780 ± 70 yr before the present (BP) (Wk-8548), whereas 18 intact seeds from the same deposits (Fig. Here, we present an additional 51 dates on seeds from the South Island (Fig. Of these, 29 seeds were from a deposit at Nguroa Bay (, Fig.